7022 aluminium alloy explained

A7022 T651
Density:	2.77 g/cm^3
Youngs Modulus:	70 GPa
Elongation:	6%
Poissons Ratio:	0.33
Hardness Rockwell:	81 HRB
Thermal Conductivity:	165 W/m*K
Linear Expansion:	2.35*10^−5 K^−1

7022 aluminium alloy is an alloy in the wrought aluminium-zinc family (7000 or 7xxx series). It is one of the more complex grades in the 7000 series, with at least 87.85% aluminium by weight.

Like most other highly alloyed alloys, 7022 is a high strength alloy, with yield strength of 370 MPa. Designed to be resistant to stress corrosion cracking, it has decent corrosion and oxidation resistance comparable to 7075 aluminium alloy^[1] but worse than 7039 aluminium alloy. Good machinability, thermal conductivity and dimensional stability make 7022 alloy a material of choice for plastic injection molds.^[2]

7022 alloy can be heat treated to increase tensile strength in expense of workability, with most common grade been T651.

Notes: Alternative names for 7022 alloy are A7022 and AA7022.

Chemical Composition

1. Aluminium: 88.35 to 92.4%
2. Zinc: 4.3 to 5.2%
3. Magnesium: 2.6 to 3.7%
4. Copper: 0.5 to 1.0%
5. Manganese: 0.1 to 0.4%
6. Chromium: 0.1 to 0.3%
7. Silicon: 0.5% max
8. Iron: 0.5% max^[3]
9. Titanium: 0.2% max
10. Zirconium: 0.2% max
11. Other: 0.15% max

See also

• Aleris (first maker of A7022)

Notes and References

1. https://archive.org/details/DTIC_ADA516812 General Corrosion Resistance Comparisons of Medium- and High-Strength Aluminum Alloys for DOD Systems Using Laboratory-Based Accelerated Corrosion Methods
2. http://www.sahamit.co.th/index.php/en/aluminium-alloy-th/7022-aluminium-alloy Sahamit machinery 7022
3. http://matweb.com/search/DataSheet.aspx?MatGUID=45cc3d2c44544b45ac61cc3c01ab28e4 matweb.com 7022 Aluminum Composition Spec